Electric connector locking means



May 11, 1965 E. HALE ELECTRIC CONNECTOR LOCKING MEANS Filed Jan. 9, 1964 INVENTOR. f. #411 rron/var United States Patent 3,183,470 ELECTRIC CONNECTOR LOCKING MEANS Leigh E. Hale, 1891 Flower St., Bakersfield, Calif. Filed Jan. 9, 1964, Ser. No. 336,754 7 Claims. (Cl. 339-82) This invention pertains to electric cord locking means and, more particularly, to locking means arranged to engage a pair of electric connectors such as a connected electric plug and socket to prevent either accidental or intentional separation of said plug and socket except by authorized personnel.

Particularly in various types of construction work and in any other type or" work where electric extension cords are of a temporary nature and must have substantial length, it becomes necessary to connect a plurality of electric cords together in series by their plugs and sockets to reach from a source of current to a particular tool at the job site. At present, certain commercial plugs and sockets, especially for industrial use, have locking means operated by a twisting movement to prevent accidental sep aration resulting solely from longitudinal pull upon two or more connected cords. Especially Where such connected cords supply current to an electric tool at a distance from the source of current, and particularly if a substantial number of cords have been connected together to supply current to said tool, it is most inconvenient and time consuming to have to locate the disconnection and reconnect plugs and sockets that have been separated, especially those disconnected by unauthorized persons.

Many connectable plug and socket constructions are available which have means to prevent accidental separation thereof but disconnection of such a plug and socket can be readily accomplished by anyone, whether authorized or not. As a result, it is not uncommon for Workmen on a job who need electric current, to disconnect such connected series of electric cords for their own use, regardless of the inconvenience to the original user of the connected cords. Such an occurrence results in an annoying waste of time, besides occasionally precipitating an extremely hazardous situation for the man rightfully depending upon the connected cords. When a connected series of electric cords is used in an obsecure or remote location such as inside a large tank, the hold of a ship, or on the opposite side of a solid wall or partition, for example, the operation of a tool or mechanism thereby cannot be observed readily by other workmen. Safe working conditions under such circumstanes also may absolutely depend upon maintaining such an electric line intact. A ventilating fan supplied by such a line, where uninterrupted ventilation is vital, must be maintained in operation, for example, or life may be endangered. These are but a few of many situations relying upon the use of connected electric cords and such examples are not to be regarded as restrictive.

It is the principal object of the present invention to provide locking means which are attachable to a pair of connected electric connectors such as a plug and socket, said locking means being engageable with the connected plug and socket in such a Way as to prevent disconnection of the plug and socket except by authorized personnel having a key, for example, to operate a suitable lock associated with said locking means.

Another object of the invention is to provide locking means of the aforementioned type which is relatively inexpensive to manufacture, yet is highly efiective to prevent unauthorized separation of an electric plug and socket, several specific examples of suitable constructions being illustrated in the drawing and described hereinafter.

A further object of the invention is to provide electric cord locking means of the types referred to above which preferably may be formed by die-stamping from sheet metal and inexpensively fabricated into a completed construction.

Still another object of the invention is to provide electric cord locking means composed of a pair of similar members having spaced means to engage ends of electric cords connected by an electric plug and socket so as to prevent unintentional or unauthorized separation thereof, said similar members being relative to one another so as to engage them, or disengage them only by authorized personnel such as those having key means by which such disengagement of the members may be effected.

Still another object of the invention which is ancillary to the foregoing objects is to provide a pair of similar members which are preferably stamped from sheet metal and are generally U-shaped, the outer ends of the legs Of the members being movably interconnected to permit engagement of the locking means relative to a connected electric plug and socket and movement of the members into lock-ing position in which they are retained by appropriate key-operated locking means.

Details of the foregoing objects and of the invention, as well as other objects thereof, are set forth in the following specification and illustrated in the accompanying drawing comprising a part thereof.

In the drawing:

FIG. 1 is a view showing one embodiment of electric connector locking means, incorporating the principles of the present invention, illustrated in the operative position thereof relative to a connected electric plug and socket on fragmentarily illustrated end portions of electric cords.

FIG. 2 is an end view of the locking means illustrated in FIG. 1 and showing, in full lines, the pair of members comprising said locking means in separated or inoperative position, and in broken lines, said members are shown in abutting, operative position.

FIG. 3 is a fragmentary view of a modification of the embodiment of locking means in FIG. 1, said modification employing insulating means to surround the electric cord connected to the electric socket or plug with which the locking means is associated in operative position.

FIG. 4 is an end view of a pair of similar-locking members interconnected by another embodiment of means from those shown in FIGS. 1 through 3.

FIG. 5 is a fragmentary perspective view of one end of one of the locking members comprising the embodiment shown in FIG. 4.

FIG. 6 is a fragmentary perspective view of one end of the other of the locking members illustrated in FIG. 4 and arranged to engage the end of the member shown in FIG. 5.

FIG. 7is a fragmentary view illustrating a modification of the embodiment illustrated in FIGS. 4 through 6 to provide insulating means in the locking members of said embodiment.

FIG. 8 is an end view of the modification of construction shown in FIG. 7 as seen from the right-hand end thereof as viewed on said sheet. Referring to FIGS. 1 through 3, one embodiment of the present invention is illustrated therein. An exemplary, heavy-duty type electric plug 10 of the type normally used on construction jobs, is shown connected to a complementary electric socket 12; such electric plug and socket respectively are connected to the ends of conventional flexible electric cords 14. The purpose of the present invention is to provide means to maintain said plug 10 and socket 12 against accidental or either intentional or unintentional separation except by authorized personnel and particularly someone having either knowledge of the combination-type padlock, or a key capable of opening suitable lock means such as a padlock.

The embodiment illustrated in FIGS. 1 through 3 comprises a pair of preferably similar, relatively movable locking members 16 and 18. In the preferred construction of these members, they are substantially U-shaped and, especially for economies in manufacturing and assembly but without being detrimental to satisfactory function and long life, said members may be formed by stamping from suitable thickness of sheet metal such as sheet steel. More particularly, they may very conveniently and effectively be formed by progressive dies which in the initial operation form the blank, in a subsequent operation form a preferably semi-cylindrical curved portion 20, the inner surface of which defines a recess 21, and the final operation of the die forms the interfitting hinge members 22 and 24 which are connected by a conventional hinge pin 26. In the preferred construction of the hinge arrangement, tongues are formed respectively on the members 16 and 18, integrally therewith, and are shaped into the conventional interfitting hinge members 22 and 24 for reception of the pin 26, thereby saving expense which otherwise would be incurred in connecting conventional hinges to the members 16 and 18.

In view of the foregoing, it will be seen that, actually, the embodiment of locking means shown in FIGS. 1 through 3 and including locking members 16 and 18 is somewhat in the form of an odd-shaped hinge. The outer ends of the legs of the U-shaped members 16 and 18 are flexibly and preferably pivotally connected together by the hinge pins 26, said legs also being spaced apart a sufiicient distance to receive therebetween the connected electric plug and socket 12. A reasonable clearance space is provided between the opposite ends of said electric plug and socket and the corresponding inner surfaces of the legs of the locking members but such clearance is not sufiicient to permit any appreciable amount of separation of the electric plug and socket from each other.

The intermediate portions 28 of the locking members 16 and 18 are provided with aligned openings or holes 30 which, when the locking members are in their operative or abutting positions as shown in broken lines in FIG. 2, readily receive the bail 32 of a padlock 34. It is to be understood that this type of lock is not to be regarded as restrictive inasmuch as other forms of locking memhere or means may be utilized but, in accordance with the spirit of the present invention, such locking means should be such that only. authorized personnel will he possessed either of knowledge or means by which said locking mechanism can be operated so as to permit movement of the locking members 16 and 18 to the inoperative, full line positions thereof shown in FIG. 2, for purposes of removing the locking mechanism from the electric plug and socket to permit separation thereof, or to assemble the locking means in locking relationship with a connected assembly of electric plug 10 and socket 12 so as to prevent separation thereof except by authorized personnel.

Referring to FIG. 3, a modification of the structure basically shown in FIGS. 1 and 2 is illustrated which comprises insulation means 36 which at least covers the inner, semi-cylindrical surface of curved portion 20 of each of the locking members 16 and 18. In the embodiment shown specifically in the figure, such insulation may comprise relatively simple means such as a short length of flattened insulation tubing clipped onto the curved portion 20 of the locking members, the thickness thereof being adequate to provide effective insulation against any possibility of the electrical conductors of the cords 14 becoming shorted through chafing or any other penetrat ing action sustained by the insulation on said cords. If preferred, appropriate molded forms of preshaped insulating members may be formed from suitable rigid or flexible insulating material and inserted within the recesses 21 and, either by cement or otherwise, being fixedly connected to the curved portions 20. I

The embodiment of electric connector locking means illustrated in FIGS. 4 through 6, while employing the basic principles of the embodiment illustrated in FIGS. 1 through 3, conceivably may be even less expensive to manufacture. Essentially, said embodiment comprises a pair of similar locking members 16 and 18, each of which have intermediate portions 28 provided with aligned openings or holes 30' to receive suitable locking means such as padlock 34 of FIG. 1.

The legs of the U-shaped locking members 16' and 18' also are provided with semi-cylindrical curved portions 20' for receiving the electric cords in the manner illustrated in FIGS. 1 and 3. Rather than fixedly connect the locking members 16 and 18' permanently together however as in the embodiment shown in FIGS. 1 through 3, the embodiment in FIGS. 4 through 6 comprises separable connecting means in the form of complementary and interfitting means provided on the outer ends of the legs of the locking members 16' and 18. These interfitting connections comprise a slot 36 formed in each of the legs of locking member 18', and a tongue 38 formed on the outer ends of each of the legs of locking members 16'. Details of the tongues 38 and slots 36 are best shown in FIGS. 5 and 6. To permit using a single die to form both members 16' and 18, one leg of each member could have a slot 36 therein and the other leg have a tongue 38 thereon.

When the members 16' and 18 are disposed in abutting, operative, locking position as shown in FIG. 4, and are held together by the padlock 34, the design of the tongues 38 and the slots 36 is such that the engagement of the connected cords is secured. When in locked position, the intermediate yoke portions 28' of the locking members are in such position that the holes 30' therein will be in alignment for the reception of an appropriate locking means such as padlock 34. It will be understood that even though the U-shaped, locking members 16 and 18' are not shown in their entirety in FIGS. 4 through 6, the same are substantially U-shaped and of the general configuration of the clamping members 16 and 18 of the embodiment shown in FIGS. 1 through 3.

Referring to FIGS. 7 and 8, there is illustrated therein a variation of the locking means shown in FIGS. 4 through 6. Pertinent reference numerals employed in FIGS. 4 through 6 are used in FIGS. 7 and 8. In this latter modification, insulating means 40 is shown which is semi-cylindrical, molded rubber or synthetic resin members 42 having transversely extending, annular flanges 44 formed on the opposite ends thereof to assist in securing the insulating members 42 within the curved portions 20'. The longitudinal opening formed by the inner surfaces of the semi-cylindrical insulating sleeves 42 will be adequate to receive electric cords 14 there-- through and insure insulation from the metal of locking members 16' and 18'. If preferred, flattened tubes of insulating material may he slipped over the curved portions 20, rather than using means 40.

The present invention gives an additional benefit in preventing unauthorized persons taking and making use of a contractors electric cord which he may have on a job for his own later use. This is accomplished merely by joining the ends of a single cord by its plug and socket and locking them together by this device. This will prevent such a spare cord being appropriated by others, but it will be ready for the owners use when he wants it.

From the foregoing, it will be seen that the present invention provides simple but highly effective means for securing connected electric connectors such as plugs and sockets against both unauthorized as well as accidental separation, thereby avoiding much wasted time, annoyance, and inconvenience in the use of multiple electric cords connected in a series especially on construction jobs and for various other purposes where relatively long temporary power lines are required. The construction is such that all embodiments illustrated and described herein are of a very simple and relatively inexpensive nature, whereby the use thereof does not noticeably increase the cost of providing electric cords for such uses. To prevent the use of key-type locking means which require authorized personnel to carry keys with them, combination-type padlocks may be used, if desired. Also, while only a padlock has been illustrated as comprising the actual locking element, it is to be understood that various other types of locking means may be employed. One such type is that in which interengaging locking means are formed in the clamping members so as to be of a concealed nature when they are in operative position and the invisible locking member is operably only by a peculiar shape of tool, for example, carried only by authorized personnel.

While the invention has been described and illustrated in its several preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as claimed.

I claim:

1. Locking means to prevent the separation of two connected electric connectors and comprising in combination, a plurality of relatively flat U-shaped members arranged for relative movement between operative locking position and inoperative position, the bight portion of said members extending between the opposite ends of said electric connectors and the legs of said members heing movably interconnected to receive electric cords 6 claim 1 in which said U-shaped members have clearance means to receive portions of electric cords connected to said electric connectors.

3. The electric connector locking means set forth in claim 2 further including insulation means in said clearance means between said cords and legs of said U-shaped members.

4. The electric connector locking means set forth in claim 1 in which the movable interconnection between the legs of said U-shaped members comprises hinges.

5. The electric connector locking means set forth in claim 1 further characterized by said members being formed by stamping from sheet metal.

6. The electric connector locking means set forth in claim 4 further characterized by said locking means comprising openings on said members aligned with each other when said members are in operative position to receive locking means operated by key-like means possessed only by authorized personnel.

7. The electric connector locking means set forth in claim l further characterized by said outer ends of said legs being interconnected by complementary interfitting means incapable of being separated when said members are in operative position to be locked relative to a connected electric plug and socket.

References Cited by the Examiner UNITED STATES PATENTS 813,526 2/06 Simpson 339-251 1,762,203 6/30 Teipel 33982 X 2,464,893 3/49 Ross 339-76 2,473,321 6/49 Yanko 339 FOREIGN PATENTS 94,5 82 10/23 Austria. 254,911 7/26 Great Britain.

JOSEPH D. SEERS, Primary Examiner. 

1. LOCKING MEANS TO PREVENT THE SEPARATION OF TWO CONNECTED ELECTRIC CONNECTORS AND COMPRISING IN COMBINATION, A PLURALITY OF RELATIVELY FLAT U-SHAPED MEMBERS ARRANGED FOR RELATIVE MOVEMENT BETWEEN OPERATIVE LOCKING POSITION AND INOPERATIVE POSITION, THE BIGHT PORTION OF SAID MEMBERS EXTENDING BETWEEN THE OPPOSITE ENDS OF SAID ELECTRIC CONNECTORS AND THE LEGS OF SAID MEMBERS BEING MOVABLY INTERCONNECTED TO RECEIVE ELECTRIC CORDS THEREBETWEEN, AND LOCKING MEANS OPERABLE BY KEY-LIKE MEANS ENGAGING SAID MEMBERS TO HOLD SAID BIGHT PORTIONS OF SAID MEMBERS AGAINST APPRECIABLE SEPARATION WHEN IN OPERATIVE LOCKING POSITION RELATIVE TO A PLURALITY OF CONNECTED ELECTRIC CONNECTORS AND THEREBY PREVENT SEPARATION OF SAID ELECTRIC CONNECTORS EXCEPT BY AUTHORIZED PERSONNEL. 